Researchers have associated gay marriage legalization with a decrease in suicide attempts among teenagers.
The findings were published in the journal JAMA Pediatrics.
The study was led by Julia Raifman, a postdoctoral fellow in the Department of Epidemiology at the Bloomberg School of Public Health of Johns Hopkins University in Baltimore, MD.
According to the Centers for Disease Control and Prevention (CDC), suicide is the third leading cause of death among 10-24-year-olds in the U.S., accounting for 4,600 deaths each year.
In recent years, there seems to have been a dramatic increase in suicide rates in the U.S, particularly among adolescents. Gay and bisexual teenagers seem to be particularly vulnerable, as almost a third - 29 percent - of those who identified as a sexual minority in the current study reported trying to commit suicide in the past year.
In comparison, 6 percent of heterosexual high-school students reported attempting suicide.
The new research suggests that the legalization of same-sex marriage - which occurred for the first time in the state of Massachusetts in 2003 - has had a positive impact on teenage suicide rates.
Analyzing the effect of same-sex marriage legalization on teenagers
Raifman and her team examined data collected from the Youth Risk Behavior Surveillance System (YRBSS) between 1 January, 1999, and 31 December, 2015. The YRBSS is a CDC-supported survey with a participation rate of over 60 percent.
The data was collected from 32 of the 35 states that had implemented pro-gay marriage policies between the 1 January, 1999, and 31 December, 2015. The researchers also compared this data with yearly changes in suicide attempts among teens in 15 states that had no legislation allowing same-sex marriage.
Raifman and colleagues used linear regression models to adjust for variables related to the state, age, sex, or race/ethnicity. They also used Taylor series to linearize standard errors.
Finally, the scientists adjusted for gay and lesbian teenagers by including an interaction between belonging to a sexual minority and living in a pro-same-sex-marriage state.
In total, the study included 762,678 high-school students with a mean age of 16.
Same-sex marriage policy linked to 14 percent drop in suicide attempts
Almost 29 percent of the students who identified as part of a sexual minority said they had attempted suicide before same-sex marriage was legalized.
The analysis found a 7 percent relative decrease in suicide attempts among teens after same-sex marriage was legalized. This amounts to 134,000 fewer suicide attempts per year.
Most of this decline was concentrated among teenagers pertaining to a sexual minority, where gay marriage legalization was linked to a 14 percent decline in suicide attempts. No reduction in suicide attempts was noted in states where gay marriage was not implemented.
The observed effects lasted for a minimum of 2 years after legalization.
"These are high-school students so they are not getting married anytime soon, for the most part. Still, permitting same-sex marriage reduces structural stigma associated with sexual orientation. There may be something about having equal rights - even if they have no immediate plans to take advantage of them - that makes students feel less stigmatized and more hopeful for the future."
Dr. Julia Raifman
Although being a teenager is difficult, Raifman adds, the data available shows large disparities between the mental well-being of sexual minorities and that of heterosexual teenagers. Lawmakers should keep this in mind when they make policy decisions, Raifman suggests.
"We can all agree that reducing adolescent suicide attempts is a good thing, regardless of our political views," she says. "Policymakers need to be aware that policies on sexual minority rights can have a real effect on the mental health of adolescents. The policies at the top can dictate in ways both positive and negative what happens further down."